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US 12,601,922 B2Granted
Waveguides with enhanced modal densities
AssigneeCorning Incorporated
InventorRobert Adam Modavis
Life of this patent
Estimating the term…
Abstract
A device for projecting a virtual- or augmented-reality image may include a waveguide and an in-coupler directing light into the waveguide such that the light is propagated through the waveguide via total internal reflection. The waveguide may include a core, a substrate, and a stack of thin films overlaying a surface of the core. A refractive index of at least one of the thin films of the stack may differ from that of the core. Adjacent thin films may have different refractive indices from one another.
Claims18
A device for projecting a virtual-or augmented-reality image, the device comprising:
- a waveguide;
- and
- an in-coupler directing light into the waveguide such that the light is propagated through the waveguide via total internal reflection;
- wherein the waveguide comprises:
- a core;
- a substrate having a thickness greater than or equal to 20 μm and less than or equal to 600 μm;
- and
- a stack of thin films overlaying a surface of the core, wherein:
- the stack comprises at least three thin films overlaying one another in the stack;
- the stack has a thickness less than 50 μm;
- a refractive index of at least one of the thin films differs from that of the core;
- adjacent thin films have different refractive indices from one another;
- and
- the stack of thin films is configured to satisfy one of the following:
- wherein the stack of thin films overlays a first major surface of the core, wherein the substrate is disposed on a second major surface of the core opposite the first major surface of the core, and
- wherein
- ❘
- "\[LeftBracketingBar]"
- d
-
- ∅
- c
- d
-
- θ
- ❘
- "\[RightBracketingBar]"
- is greater relative to that of the core without the stack of thin films over one or more or a range of incidence angles between the critical angle θcritical of the core and 90°, where q is an incidence angle of the light propagating inside the core of the waveguide via total internal reflection, and øc represents a phase change of the light upon reflection from the first major surface of the core;
- or
- wherein the stack of thin films overlays the second major surface of the core, and wherein the stack of thin films is disposed between the core and the substrate,
- ❘
- "\[LeftBracketingBar]"
- d
-
- ∅
- s
- d
-
- θ
- ❘
- "\[RightBracketingBar]"
- is greater relative to that of the core without the stack of thin films over one or more or a range of incidence angles between the critical angle θcritical of the core and 90°, where Øs represents a phase change of the light upon reflection from the second major surface of the core.
39 more elements
A head-mounted device, comprising:
- a display;
- a waveguide;
- an in-coupler configured for coupling light emitted by the display into the waveguide at a first location of the waveguide such that the light is propagated through the waveguide via total internal reflection to a second location of the waveguide;
- and
- an out-coupler configured for coupling the light out of the waveguide at the second location of the waveguide and for projecting the light into a user's eye;
- wherein the waveguide comprises:
- a core comprising:
- a first major surface, a second major surface opposite the first major surface, and a thickness defined by a distance between the first major surface and the second major surface, wherein the thickness of the core is less than or equal to 2,000 μm;
- and
- a coating comprising:
- a thickness that is less than or equal to 50 μm;
- a first layer disposed on the first major surface of the core and having a first refractive index that is different from the refractive index of the core;
- and
- a second layer disposed on the first layer and having a second refractive index that is different from the first refractive index of the first layer;
- and
- wherein the propagation of the light through the waveguide via total internal reflection satisfies the following:
- κ1h−Øc−Øs=mπ, where κ1=n1k cos θ, n1 is the refractive index of the core, k=2π/λ, λ is the wavelength of the light, θ is an incidence angle of the light propagating inside the core of the waveguide via internal reflection, h is the thickness of the core, Øc represents a phase change of the light upon reflection from the first major surface of the core, and Øs represents a phase change of the light upon reflection from the second major surface of the core, and m is an integer and specifies a mode number associated with the incidence angle θ;
- and
- wherein the coating is configured such that
- ❘
- "\[LeftBracketingBar]"
- d
-
- ∅
- c
- d
-
- θ
- ❘
- "\[RightBracketingBar]"
- is greater relative to that of the core without the coating over one or more or a range of incidence angles between the critical angle θcritical of the core and 90°.
28 more elements
A waveguide for transporting a virtual-or augmented-reality image, comprising:
- a core comprising:
- a first major surface, a second major surface opposite the first major surface, and a thickness defined by a distance between the first major surface and the second major surface, wherein the thickness of the core is greater than or equal to 5 μm to 2,000 μm;
- and
- a coating disposed on the first major surface of the core, wherein the coating comprises:
- a first layer disposed on the first major surface of the core and having a first refractive index less than or equal to 1.6 and different from the refractive index of the core;
- a second layer disposed on the first layer and having a second refractive index that is greater than or equal to 1.6 and different from the first refractive index of the first layer;
- a third layer disposed on the second layer and having a third refractive index that is less than or equal to 1.6 and different from the second refractive index of the second layer;
- and
- a thickness that is greater than or equal to 1 nm and less than or equal to 50 μm;
- wherein propagation of light through the waveguide via total internal reflection satisfies the following:
- κ
- 1
-
- h
- -
- ∅
- c
- -
- ∅
- s
- =
- m
-
- π
- where k1=n1k cos θ, n1 is the refractive index of the core, k=2π/λ, λ is the wavelength of the light, θ is an incidence angle of the light propagating inside the core of the waveguide via internal reflection, h is the thickness of the core, Øc represents a phase change of the light upon reflection from the first major surface of the core, and Øs represents a phase change of the light upon reflection from the second major surface of the core, and m is an integer and specifies a mode number associated with the incidence angle θ;
- and
- wherein the coating is configured such that
- ❘
- "\[LeftBracketingBar]"
- d
-
- ∅
- c
- d
-
- θ
- ❘
- "\[RightBracketingBar]"
- is greater relative to that of the core without the coating over one or more or a range of incidence angles between the critical angle θcritical of the core and 90°.
36 more elements
Dependencies are inferred from the claim text.